Apparatus for use with underwater wells



March 17, 1970 w. H. PETERSEN APPARATUS FOR USE WITH UNDERWATER WELLS 3 Sheets-Sheet 1 Filed May 23, 1968 INVENTORI WILLIAM H. PETERSEN HIS ATTORNEY FIG.

March 17, 1970 w. H. PETERSEN 3,500,905

APPARATUS FOR USE WITH UNDERWATER WELLS Filed May 23, 1968 3 Sheets-Sheet 2 L50 :i I I 1: 59 --58 n a. i

FIG. 6

INVENTORZ WILLIAM H. PETERS N HIS ATTORNEY W. H. PETERSEN APPARATUS FOR USE WITH UNDERWATER WELLS March 17, 1970 3 Sheets-Sheet 3 Filed May 23. 1968 INVENTORZ WILLIAM H. PETERSEN BY! paw HIS ATTORNEY United States Patent Oflice 3,500,905 Patented Mar. 17, 1970 3,500,905 APPARATUS FOR USE WITH UNDERWATER WELLS William H. Petersen, Houston, Tex., assignon to Shell 011 Company, New York, N.Y., a corporation of Delaware Filed May 23, 1968, Ser. No. 731,496 Int. Cl. E21b 7/12, 15/02 US. Cl. 166.5 6 Claims ABSTRACT OF THE DISCLOSURE This invention relates to offshore operations concerned with drilling, producing, servicing, and maintaining underwater wells, and pertains more particularly to apparatus lowerable from a floating vessel for use in remotely handling components, tools and other equipment associated with the well.

In an attempt to locate new oil fields, an increasing amount of well drilling has been conducted at offshore locations, such, for example, as off the coasts of California, Louisiana and Texas and, more recently, off the coast of Alaska and in the North Sea. As a general rule, the strings of casing in a well, together with the tubing string or strings, extend to a point above the surface of the water where they are closed in a conventional manner that is used on onshore wells, with a conventional wellhead assembly being attached to the top of the casing. Recently, methods and apparatus have been provided for drilling and completing the well wherein both the well and casinghead and subsequently the wellhead assembly and easing closure device are located under water at a depth suflicient to allow ships to pass over them.

In the case of these latter underwater installations, some means must be provided to carry out the various required operations with respect to the underwater well and the wellhead assembly associated therewith. This problem becomes especially diflicult when the underwater well site is at such a distance below the surface of the ocean or other body of water so as to preclude the use of human divers. Accordingly, a wide variety of special tools and components have been devised and utilized to remotely carry out the desired underwater operations from vessels floating on the surface of the water over the well site. These tools and components are lowered from the vessel to the location of the well by any one of a variety of methods well known in the art such as by means of pipe strings and/or guide lines extending downwardly from the floating vessel.

In the event pipe strings are used to carry out these operations, some means must be employed to prevent buckling and/ or breakage of the pipe string or equipment depending therefrom due to the rise and fall of the vessel on the surface of the water and the consequential variance of the distance between the vessel and the underwater installation.

SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to provide apparatus whereby operations may be carried out with respect to an underwater well from a floating vessel, such apparatus being of a telescoping construction to compensate for relative movement between the vessel and the underwater well installation.

This object has been attained in the present invention by providing apparatus for carrying out underwater well site operations from a floating vessel which includes two relatively movable telescoping members, one of said members adapted for attachment to a pipe string or other similar means depending from the vessel and the other of said members adapted to hold the component, tool, etc., which is to be lowered, retrieved, or otherwise manipulated from the vessel. Sheave means is mounted with respect to the telescoping members in such a manner as to take up slack on control lines or cable means associated therewith in response to the telescoping action of the members. In addition, a cushioning system, including gas charged hydraulic cylinders mounted on one of said members acting in cooperating with pistons mounted on the other of said members, is provided to absorb end wise impact energy imparted to the apparatus.

DESCRIPTION OF THE DRAWING Other objects, purposes, and characteristic features of the present invention will be obvious from the accompanying drawings and from the following description of the invention. In describing the invention in detail, reference will be made to the accompanying drawings in which like reference characters designate corresponding parts throughout several views, and in which:

FIGURE 1 is a diagrammatic view illustrating apparatus according to the present invention being lowered into the vicinity of an underwater wellhead assembly by means of a pipe string depending from a floating vessel;

FIGURE .2 is an enlarged, detailed longitudinal view showing apparatus according to the present invention in association with flowline connecting equipment and being lowered along guide line means;

FIGURE 3 is an enlarged detail view in partial cross section of the impact cushioning system utilized on apparatus according to the present invention;

FIGURE 3A is a cross-sectional view taken along line 3A3A of FIGURE 3;

FIGURES 4 and 5 are enlarged, cross-sectional views taken along line 4-4 and line 5-5, respectively, of FIG- URE 3;

FIGURE 6 is an enlarged, cross-sectional view illustrating details of the cushioning arrangement employed in the apparatus according to the present invention; and

FIGURES 7 and 8 are enlarged, detailed longitudinal views illustrating relative positions assumed by elements of the apparatus according to the present invention during dilfering stages in the operation thereof.

Referring to FIGURE 1 of the drawing, a vessel or platform is generally represented by numeral 11. The vessel or platform 11 is of any suitable type, preferably one, as illustrated, floating at the surface of a body of water 12 and substantially fixedly positioned at a preselected location by suitable vessel positioning means or by being anchored to the sea bed or ocean floor 13 by suitable anchors (not shown) connected to the anchor lines 14 and 15. Equipment of this type may be used when carrying on operations with respect to wells positioned from 100 to 1,500 feet or more under water. Vessel 11 is equipped with a suitable derrick 16 as well as other conventional auxiliary equipment such as a hoist system 17, rotary table 18, etc. The derrick 16 may be positioned over a drilling slot or well 19 which extends vertically through the vessel in a conventional maner. When using the equipment of the present invention, the slot 19 in the vessel may be either centrally located or extend in from one edge. However, operations also may be carried out over the 'side of the vessel without use of the slot.

An underwater production assembly 21 including wellhead assembly 22 is shown as being positioned on the ocean floor 13 and being fixedly secured thereto by a conductor pipe or well casing 23 which extends into the ocean floor .13 and is preferably cemented therein. Casing 23 passes through equipment base 24 of the production assembly with the interior thereof in fluid communication with wellhead assembly 22 in the usual manner. The equipment base 24 is provided with a plurality of fixedly positioned upstanding guide columns 25, 26 and 27. Guide lines or cables 28, 29 and 30 are affixed to the guide columns and extend upwardly therefrom through the water to vessel 11 where they are preferably secured to constant tension hoists 31 and 32 Wellhead assembly 22 may be of any construction suitable for underwater production operations and for illustration purposes it may be assumed that assembly 22 has been previously lowered into position from vessel 11 along guide lines 29 and 30 in a manner well known in the art. Since the wellhead assembly forms no part of the present invention and may be of any suitable type, it is not deemed necessary to describe it in greater detail. US. Patent No. 3,136,363, issued June 9, 1964, to Yetman et al. may be referred to for an example of onesuitable underwater wellhead assembly design. As with respect to the assembly disclosed in that patent, wellhead assembly 22 includes at least one fiowline 33 which preferably bends in a long sweeping curve to a substantially horizontal position, terminating in coupling member 34 of any suitable design. Flowline 33 is in fluid communication with production tubing (not shown) extending down into casing 23 into the interior of the well in a known manner.

Referring now to FIGURES 1 and 2, a pipe string 39 is illustrated as depending from vessel 11 and having attached to the lower end thereof by any suitable connector means the apparatus according to the present invention indicated generally by reference numeral 40. Apparatus 40 includes an upper tubular member 41 attached to pipe string 39 by any suitable connector arrangement and a lower tubular member 42. Lower tubular member 42 has an outer diameter somewhat smaller than the inner diameter of upper tubular member 41 and extends upwardly into the interior of upper tubular member 41 in a manner that can be most clearly seen in FIGURE 3.

With particular reference to this latter figure, lower tubular member 42 has integrally formed thereon a flange member 43 which is disposed within the interior or throughbore of upper tubular member 41. A plate member 44 is positioned on lower tubular member 42 below upper tubular member 41. As may be seen most clearly with reference to FIGURE 3A, plate member 44 defines a throughbore 35 which is somewhat larger than the outer diameter of lower tubular member 42 with the result that plate mmeber 44 is slidable on tubular member 42. Two notches or indents 36 and 37 are formed in plate member 44 to communicate with throughbore 35.

A plurality of integral ribs 45a, 45b, 45c and 45d are formed in parallel fashion along that portion of lower tubular member 42 lying between flange members 43 and 44 as viewed in FIGURES 3 and 5. Ribs 45a and 450 are formed over substantially the full length of lower tubular member 42 while ribs 45b and 45d terminate further up tubular member 42 and in FIGURES 3 and 5 are illustrated as being in abutting relation with the upper surface of plate member 44. Ribs 45a and 450, on the other hand, are accommodated by notches 36 and 37 of lower tubular member 42 (FIGURE 3A) and are freely slidable therein. Ribs 45a and 45c maintain proper rotational alignment between members 41 and 42 throughout the ax al stroke of the apparatus.

Upper tubular member 41 flares outwardly at the bottom thereof to form integral skirt member 46 (FIGURE 3). In abutting relationship with skirt member 46 is a bushing member 47 which may be maintained in position by any known expedient such as by being welded or otherwise secured to skirt member 46. If desired, an end plate 48 may be secured in any known fashion to the bushing member on the side of the bushing member opposite the skirt member 46. In addition, a wear ring 49 may be maintained between bushing member 47 and end plate 48 in the manner illustrated in FIGURES 3 and 4.

Mounted on skirt member 46 and extending upwardly therefrom are cylinders 50 and 51 in which are disposed piston rods 52 and 53 respectively. Piston rods 52 and 53 are connected at their lower ends in any known manner, such as by means of screw threads, lock nuts, etc., to plate member 44 disposed on lower tubular member 42. The piston rods pass through aligned throughbores in skirt member 46, bushing member 47 and end plate 48 in the manner illustrated most clearly in FIGURE 3 with the respective dimensions of the throughbores and the piston rods being such that the rods have freedom of axial movement within the throughbores. O-ring or other type seals are provided to ensure fluid-tight engagement between piston rods 52 and 53 and the lower packing gland element at the base of cylinders 50 and 51. For example, seal 52a is shown in operative engagement with piston rod 52 to prevent the passage of fluid therebetween. As may be seen most clearly with reference to FIGURES 3 and 4, lower tubular member 42 passes through a central throughbore 42a formed by members 46 and 47 and end plate 48 into the interior of upper tubular member 41.

Housed within each of cylinders 50 and 51 is a piston member such as piston member 58 illustrated in FIGURE 6 with particular reference to cylinder 50. The dimensions of the piston members are such that the outer cylindrical peripheries thereof are in fluid-tight engagement with the inner walls of their respective cooperating cylinders while at the same time permitting relative axial movement therebetween. As shown with respect to piston member 58 seal means such as O-ring seal 59 may be provided on the piston members to ensure this fluid-tight fit. Piston rods 52 and 53 respectively are attached to the abovementioned piston members in any known manner. In FIGURE 6, for example, piston rod 52 is illustrated as being attached to piston member 58 by means of lock nuts 60 and 61 threadedly secured to the rod on oppos te sides of the piston member. Cylinders 50 and 51 are pressurized with a gas below the piston members thus resulting in a cushioning or dampening effect on any downwardly directed forces being exerted on the piston rods in an obvious manner. The effect and operation of the abovedescribed cushioning means will be described in detail below insofar as it relates to the operation of the yet to be described remaining elements of the subject invention.

Returning once again to FIGURES l and 2, the apparatus according to the present invention is seen as being utilized to lower into operative association with underwater production assembly 21 a tool indicated generally by numeral 65, which for illustration purposes may be a fiowline connector of the general type disclosed in US. Patent No. 3,298,092, issued Jan. 17, 1967, to J. R. Dozier et al. As is more fully disclosed in that patent, a flow- ]ine connector tool such as a tool 65 is used to connect underwater flowlines (not shown) to connector couplings, such as coupling member 34 in the instant case, associated with an underwater production assembly. As stated above, however, the apparatus according to the present invention may be used as a means for landing, retrieving, or otherwise handling a wide variety of components, including tools and well components on the ocean floor and for performing numerous other tasks, such as nonroutine pulling and fishing jobs. For this reason, and since tool 65 forms no part of the present invention, it is not deemed necessary to describe this particular piece of equipment in greater detail. Tool 65, as well as any other tool and/or component to be utilized, may be attached to lower tubular member by any form of connector means such as by means of screw threads, bolts, etc.

Extending downwardly from vessel 11 along pipe string 39, apparatus 40 and thence to tool 65 is a multiconduit or conductor control cable 66 used to carry electrical, hydraulic or pneumatic signals to the various components of the flowline connector tool system. Cable 66 passes through a clamp 67 on pipe string 39 and through bracket 68 and clamp 69 fixedly mounted on upper tubular member 41 of apparatus 40. After emerging from the bottom of clamp 69, cable 66 passes around and under a rotatable sheave 70 which is preferably weighted and is mounted in any desirable manner for free axial or upand-down movement with respect to track means carried by upper tubular member 41 such as slot 71 formed therein. After passing about the bottom of sheave 70, cable 66 proceeds upwardly to a second sheave 72 which is rotatably mounted on a spindle element 73 fixedly positioned on upper tubular member 41. After looping over sheave 72, cable 66 proceeds downwardly through a guide tube 74 mounted on the lower portion of upper tubular member 41 and thence through clamp 75 to terminator element 76 mounted on lower tubular member 42 and tool 65 respectively, whereupon the separate conduits or conductors of the cable proceed into the interior of the tool itself.

The operation of the apparatus according to the present invention will now be described. After guide lines such as guide lines 28, 29, and 30 have been established between vessel 11 and underwater production assembly 21 by any of the known prior art approaches, a tool or apparatus, such as tool 65, to be lowered into position, 18 connected to lower tubular member 42 of apparatus 40 and the tools are lowered from vessel 11 as by means of pipe string 39. Cylindrical guides such as guides 80 and 81 frame-connected to tool 65 and guide 82 frame-connected to upper tubular member 41 are preferably provided to slide along one or more of the guide lines thereby providing stability during the lowering operation and positioning the tool as it is placed into engagement w th assembly 21. The lowering operation by means of a pipe string, such as pipe string 39, is carried out in the usual fashion, i.e., through the addition of individual pipe sections to the string on board vessel 11.

After the tool 65 has been landed and latched or otherwise secured in position on assembly 21, landing string 39 is continued to be lowered until apparatus 40 is in its mid-stroke position. At this point, the landing string is secured to the drilling vessel. Upper tubular member 41 will move up and down over lower tubular member 42 as the distance between vessel 11 and assembly 21 varies due to the rise and fall of the surface of the body of water 12. Proper rotational alignment is maintained be tween members 41 and 42 by ribs 45a and 450 as the apparatus strokes. As upper tubular member 41 moves in a downward direction, sheave 70 also moves downwardly within slot or track 71 to take up any slack in cable 66 due to this telescoping action in the manner illustrated in FIGURE 7. In like manner, sheave 70 will move upwardly with respect to slot or track 71 when vessel 11 rises and in consequence thereof upper tubular member 41 moves upwardly with respect to lower tubular member 42 as shown in FIGURE 8. In this manner, cable 66 is maintained under tension at all times regardless of the telescopic action of the two tubular members 41 and 42 thereby preventing possible fouling of the cable due to this action.

After the desired operations have been carried out at the well site and it is desired to remove apparatus 40 and the operating tool associated therewith to the surface of the water, the necessary disconnect operations are made by means of signals passing through cable or line 66. Pipe string 39 is then pulled upwardly to vessel 11 in the usual manner. In the event the required disconnect operations have not been carried out due to some equipment malfunction and the tool and/or wellhead component remains attached to the remainder of the underwater production assembly, the operator on board vessel 11 will be able to detect this before sutlicient upward force is exerted on pipe string 39 to cause damage to the underwater assembly 21, the tool, and/or apparatus 40. This is due to the fact that some feel will be provided by the previously described cushioning means including cylinders 50 and 51, piston rods 52 and 53 and the piston members associated therewith. Upward pull of pipe string 39 and consequently upper tubular member 41 will cause plate member 44 to contact ribs 45b and 45d, thereby halting plate member movement while at the same time pulling cylinders 50 and 51 upwardly relative to the piston members, e.g., piston member 58, which are prevented from moving upwardly due to the cooperation of plate member 44 and ribs 45b and 45d. The dampening effect of the gas in cylinders 50 and 51 upon the bottom of the piston members will prevent breakage of the equipment while at the same time giving the operator warning that the required unlocking or unlatching operation with respect to the tool has not been efiected. Remedial actions may then be carried out to correct the problem.

I claim as my invention:

1. Apparatus for carrying out operations with respect to an underwater installation from a floating vessel, said apparatus comprising:

telescoping means including at least two relatively movable members adapted to be disposed between said vessel and said underwater well installation with relative movement between said members serving to compensate for changes in the distance between said vessel and said installation;

flexible cable means extendable from said vessel to said well and extending along substantially the length of said telescoping means; and

cable takeup means mounted on said telescoping means and cooperable with said flexible cable means to take up any slack in said flexible cable means resulting from relative movement between said members. 2. Apparatus according to claim 1 including cushioning means operatively associated with said telescoping means to dampen loads applied thereto.

3. Apparatus according to claim 1 wherein said takeup means comprises sheave means mounted on at least one of said relatively movable members, said flexible cable means having at least a portion thereof maintained in contact with said sheave means during relative movement between said members.

4. Apparatus according to claim 3 wherein said telescoping means comprises a first tubular member and a second tubular member with said first tubular member lgeing relatively movable within said second tubular mem- 5. Apparatus according to claim 4 including axially extending track means carried by one of said tubular members; said sheave means comprising a first sheave cooperating with said track means and movable with respect thereto and a second sheave rotatably mounted on spindle means fixedly mounted on the tubular member carrying said track means whereby the distance between said sheave means increases as said distance between said floating vessel and said underwater installation decreases.

6. Apparatus according to claim 5 wherein said track means comprises a longitudinally extending slot formed in the wall of said second tubular member.

References Cited UNITED STATES PATENTS Koons 254172 X Postlewaite 1757 Nelson Q. 254-172 Kammerer 175-5 NILE C. BYERS, JR., Primary Examiner R. E. FAVREAU, Assistant Examiner US. Cl. X.R. 175-7; 254172 

